I know you are kidding...

but...

400 they can take no problem. I'm pretty sure the danger zone is somewhere over 1000 or 1200 watts. I'm guessing it's actually related to torque, but I do have a power meter on one of my bikes, so I know how much 400 watts actually takes. And even though I don't have one on the bike I crashed, I know I was way over 400. From feeling alone, I would estimate I was between 1000 and 1300 watts which is around the top of my instantaneous range. I can only mantain those numbers for a few seconds, but it's long enough to "do a lot of damage". Pun intended